Modern radio access technologies such as Long Term Evolution, LTE, for example generally support advanced multi-antenna features such as Spatial Multiplexing, also referred to as Multiple Input Multiple Output, MIMO. This means that the corresponding base station deployments are equipped with multiple antennas and associated transmitters.
Such a multi-antenna enabled system can be deployed as a stand-alone system, e.g. a stand-alone LTE system, or deployed together with one or more other radio access technologies such as Code Division Multiple Access, CDMA, or Wideband Code Division Multiple Access, WCDMA, or even Global System for Mobile communications, GSM.
In the latter case, in a so-called co-sited deployment, also referred to as a multi-standard base station site, the other radio access technologies are typically not designed for multi-antenna operation, or at least not optimized for such operation, and can therefore not fully exploit the available radio and multi-antenna infrastructure.
There is thus a general demand for multi-standard base station sites with improved capabilities.